Obesity is a major health problem in developed countries. Obesity puts you at greater risk of developing high blood pressure, diabetes and many other serious health problems. In the United States, the complications of being overweight or obese are estimated to affect nearly one in three American adults, with an annual medical cost of over $80 billion and, including indirect costs such as lost wages, a total annual economic cost of over $120 billion. Except for rare pathological conditions, weight gain is directly correlated to overeating.
Noninvasive methods for reducing weight include increasing metabolic activity to burn calories and/or reducing caloric intake, either by modifying behavior or with pharmacological intervention to reduce the desire to eat. Other methods include surgery to reduce the stomach's volume, banding to limit the size of the stoma, and intragastric devices that reduce the desire to eat by occupying space in the stomach.
Intragastric volume-occupying devices provide the patient a feeling of satiety after having eaten only small amounts of food. Thus, the caloric intake is diminished while the person is satisfied with a feeling of fullness. Currently available volume-occupying devices have many shortcomings. For example, complex gastric procedures are required to insert some devices.
U.S. Pat. No. 4,133,315, the contents of which are incorporated herein by reference in their entirety, discloses an apparatus for reducing obesity comprising an inflatable, elastomeric bag and tube combination. The bag can be inserted into the patient's stomach by swallowing. The end of the attached tube distal to the bag remains in the patient's mouth. A second tube is snaked through the nasal cavity and into the patient's mouth. The tube ends located in the patient's mouth are connected to form a continuous tube for fluid communication through the patient's nose to the bag. Alternatively, the bag can be implanted by a gastric procedure. The bag is inflated through the tube to a desired degree before the patient eats so that the desire for food is reduced. After the patient has eaten, the bag is deflated. The tube extends out of the patient's nose or abdominal cavity throughout the course of treatment.
U.S. Pat. Nos. 5,259,399, 5,234,454 and 6,454,785, the contents of which are incorporated herein by reference in their entirety, disclose intragastric volume-occupying devices for weight control that must be implanted surgically.
U.S. Pat. Nos. 4,416,267, 4,485,805, 4,607,618, 4,694,827, 4,723,547, 4,739,758, and 4,899,747 and European Patent No. 246,999, the contents of which are incorporated herein by reference in their entirety, relate to intragastric, volume-occupying devices for weight control that can be inserted endoscopically. Of these, U.S. Pat. Nos. 4,416,267, 4,694,827, 4,739,758 and 4,899,747, the contents of which are incorporated herein by reference in their entirety relate to balloons whose surface is contoured in a certain way to achieve a desired end. In U.S. Pat. Nos. 4,416,267 and 4,694,827, the contents of which are incorporated herein by reference in their entirety, the balloon is torus-shaped with a flared central opening to facilitate passage of solids and liquids through the stomach cavity. The balloon of U.S. Pat. No. 4,694,827, the contents of which are incorporated herein by reference in their entirety, has a plurality of smooth-surfaced convex protrusions. The protrusions reduce the amount of surface area which contacts the stomach wall, thereby reducing the deleterious effects resulting from excessive contact with the gastric mucosa. The protrusions also define channels between the balloon and stomach wall through which solids and liquids may pass. The balloon of U.S. Pat. No. 4,739,758, the contents of which are incorporated herein by reference in their entirety, has blisters on its periphery that prevent it from seating tightly against the cardia or pylorus.
The balloons of U.S. Pat. Nos. 4,899,747 and 4,694,827, the contents of which are incorporated herein by reference in their entirety, are inserted by pushing the deflated balloon and releasably attached tubing down a gastric tube. U.S. Pat. No. 4,723,547, the contents of which are incorporated herein by reference in their entirety discloses a specially adapted insertion catheter for positioning its balloon. In U.S. Pat. No. 4,739,758, the contents of which are incorporated herein by reference in their entirety, the filler tube effects insertion of the balloon. In U.S. Pat. No. 4,485,805, the contents of which are incorporated herein by reference in their entirety, the balloon is inserted into a finger cot that is attached by string to the end of a conventional gastric tube that is inserted down the patient's throat. The balloon of European Patent No. 246,999 is inserted using a gastroscope with integral forceps.
In U.S. Pat. Nos. 4,416,267, 4,485,805, 4,694,827, 4,739,758, and 4,899,747 and European Patent No. 246,999, the contents of which are incorporated herein by reference in their entirety, the balloon is inflated with a fluid from a tube extending down from the patient's mouth. In these patents, the balloon also is provided with a self-sealing hole (U.S. Pat. No. 4,694,827, the contents of which are incorporated herein by reference in their entirety), injection site (U.S. Pat. Nos. 4,416,267 and 4,899,747, the contents of which are incorporated herein by reference in their entirety), self-sealing fill valve (U.S. Pat. No. 4,485,805, the contents of which are incorporated herein by reference in their entirety), self-closing valve (European Patent No. 246,999, the contents of which are incorporated herein by reference in their entirety) or duck-billed valve (U.S. Pat. No. 4,739,758, the contents of which are incorporated herein by reference in their entirety). U.S. Pat. No. 4,723,547, the contents of which are incorporated herein by reference in their entirety, uses an elongated thick plug and the balloon is filled by inserting a needle attached to an air source through the plug.
U.S. Pat. No. 4,607,618, the contents of which are incorporated herein by reference in their entirety, describes a collapsible appliance formed of semi-rigid skeleton members joined to form a collapsible hollow structure. The appliance is not inflatable. It is endoscopically inserted into the stomach using an especially adapted bougie having an ejector rod to release the collapsed appliance. Once released, the appliance returns to its greater relaxed size and shape.
U.S. Pat. No. 5,129,915, the contents of which are incorporated herein by reference in their entirety, relates to an intragastric balloon that is intended to be swallowed and that inflates automatically under the effect of temperature. Three ways that an intragastric balloon might be inflated by a change in temperature are discussed. A composition comprising a solid acid and non-toxic carbonate or bicarbonate is separated from water by a coating of chocolate, cocoa paste or cocoa butter that melts at body temperature. Alternatively, citric acid and an alkaline bicarbonate coated with non-toxic vegetable or animal fat melting at body temperature and which placed in the presence of water, can produce the same result. Lastly, the solid acid and non-toxic carbonate or bicarbonate are isolated from water by an isolation pouch of low-strength synthetic material which it will suffice to break immediately before swallowing the bladder. Breaking the isolation pouches causes the acid, carbonate or bicarbonate and water to mix and the balloon to begin to expand immediately. A drawback of thermal triggering of inflation is that it does not afford the degree of control and reproducibility of the timing of inflation that is desirable and necessary in a safe self-inflating intragastric balloon.
After swallowing, food and oral medicaments typically reach a patient's stomach in under a minute. Food is retained in the stomach on average from one to three hours. However, the residence time is highly variable and dependent upon such factors as the fasting or fed state of the patient. Accordingly, proper timing of inflation of an intragastric balloon is a factor in successful deployment of the intragastric devices of various embodiments. Timing is selected to avoid premature inflation in the esophagus that could lead to an esophageal obstruction or belated inflation that could lead to intestinal obstruction.
Methods for verifying that the intragastric device is in the stomach are useful in that they do not rely on mere timing after administration of the intragastric device. Verification of location can be done with radiography. After a patient swallows an encapsulated balloon, radiography can be done to ensure the balloon is in the stomach after swallowing, with the encapsulated balloon visualized by a radio-opaque marker. Radiographic techniques include x-ray or fluoroscopy techniques that provide real-time images of the balloon using radiation. However, radiation may be harmful to the body if prolonged or administered in high doses. While fluoroscopy typically uses low doses of radiation, repeated use may create a risk of harm to a patient. Further, there is the risk of accidental administration of too high of a dose to a patient.
Electromagnetic-based systems and methods provide advantages over, e.g., radiography. Electromagnetism refers generally to the magnetic fields corresponding to electric currents. A current may be induced in a conducting material by the presence of a magnetic field. A magnetic field may also be induced by the presence of a current running through a conductive material. Electromagnetism has been used in many different contexts, and it presents advantages when used in the intragastric device locating and characterizing context.
Voltage-based systems and methods also provide advantages over e.g., radiography. Voltages are created when the electric potential of one point is different from that of another point. Voltage has been used in many different contexts, and it presents advantages when used in the intragastric device locating and characterizing context.
U.S. Pat. No. 8,858,432, the contents of which are incorporated herein by reference in their entirety, discloses ingestible markers incorporating a signal generating circuit. The ingestible event marker systems include an ingestible event marker (IEM) and a personal signal receiver. The IEM includes an identifier, such as a physiologically acceptable carrier, that is activated upon contact with a target internal physiological site of a body, such as digestive tract internal target site. The personal signal receiver is configured to be associated with a physiological location, e.g., inside of or on the body, and to receive a signal the IEM. During use, the IEM broadcasts a signal which is received by the personal signal receiver.
U.S. Pat. No. 8,836,513, the contents of which are incorporated herein by reference in their entirety, describes a system having an ingestible product indicating that it has been consumed. The system includes a conductive element, an electronic component, and a partial power source in the form of dissimilar materials. Upon contact with a conducting fluid, a voltage potential is created and the power source is completed, which activates the system. The electronic component controls the conductance between the dissimilar materials to produce a unique current signature. The system can be associated with food and communicate data about ingestion of food material to a receiver.
U.S. Pat. No. 8,847,766, the contents of which are incorporated herein by reference in their entirety, describes a system for physical delivery of a pharmaceutical agent. The system includes an identifier that transmits a conductive signal and consumable electrodes formed of dissimilar materials. The electrodes are configured to both generate a voltage to energize the identifier and transmit the conductive signal to the body when the first and second electrodes contact the bodily fluid.
Ultrasound-based systems and methods also provide advantages over, e.g., radiology. Ultrasound is an oscillating sound pressure wave with a frequency greater than the upper limit of the human hearing range. Ultrasound is thus not separated from ‘normal’ (audible) sound based on differences in physical properties, only the fact that humans cannot hear it. Although this limit varies from person to person, it is approximately 20 kilohertz (20,000 hertz) in healthy, young adults. Ultrasound devices operate with frequencies from 20 kHz up to several gigahertz.
Ultrasonic devices may be used to detect objects and measure distances. Ultrasonic imaging (sonography) is used in both veterinary medicine and human medicine. In the nondestructive testing of products and structures, ultrasound is used to detect invisible flaws. Industrially, ultrasound is used for cleaning and for mixing, and to accelerate chemical processes. Animals such as bats and porpoises use ultrasound for locating prey and obstacles.
Ultrasonics is the application of ultrasound. Ultrasound can be used for medical imaging, detection, measurement and cleaning. At higher power levels, ultrasonics is useful for changing the chemical properties of substances.
Medical sonography (ultrasonography) is an ultrasound-based diagnostic medical imaging technique used to visualize muscles, tendons, and many internal organs, to capture their size, structure and any pathological lesions with real time tomographic images. Ultrasound has been used by radiologists and sonographers to image the human body for at least 50 years and has become a widely used diagnostic tool. The technology is relatively inexpensive and portable, especially when compared with other techniques, such as magnetic resonance imaging (MRI) and computed tomography (CT). Ultrasound is also used to visualize fetuses during routine and emergency prenatal care. Such diagnostic applications used during pregnancy are referred to as obstetric sonography. As currently applied in the medical field, properly performed ultrasound poses no known risks to the patient. Sonography does not use ionizing radiation, and the power levels used for imaging are too low to cause adverse heating or pressure effects in tissue.
Ultrasound is also increasingly being used in trauma and first aid cases, with emergency ultrasound becoming a staple of most EMT response teams. Furthermore, ultrasound is used in remote diagnosis cases where teleconsultation is required, such as scientific experiments in space or mobile sports team diagnosis. Ultrasounds are also useful in the detection of pelvic abnormalities and can involve techniques known as abdominal (transabdominal) ultrasound, vaginal (transvaginal or endovaginal) ultrasound in women, and also rectal (transrectal) ultrasound in men.
Ultrasound has been used in many different contexts, and it presents advantages when used in the intragastric device locating and characterizing context.
Medical imaging is employed to diagnose a large number of diseases. The oldest method, dye X-ray technology, delivers high-resolution images within a short examination time; however, it has the disadvantage of exposing the patient to X-rays. Ultrasound imaging is a method of image acquisition that works without using radiation. With said ultrasound imaging, ultrasound signals are sent via an ultrasound transducer into the object to be examined and a corresponding control device receives the reflected ultrasound signals and processes the receive signals for imaging purposes.
U.S. Pat. No. 8,535,230, the contents of which are incorporated herein by reference in their entirety, describes an ultrasound device including an ultrasound transducer on a robotic arm to track an object as it moves. However, such a system is incompatible with tracking a device inside the body.
U.S. Pat. No. 8,105,247, the contents of which are incorporated herein by reference in their entirety, describes use of ultrasonic transceivers to measure the size of a gastric banding device. However, that system is intended for a stationary gastric banding device and is not directly applicable to locating and characterizing a translating, rotating and transforming intragastric device.